1. Field of the Invention
The present invention relates to shaving razors in general and, more particularly, to razor cartridges having razor blade and support assemblies positioned in a housing.
2. Background of the Invention
Modern shaving razors include one or more blades disposed within a housing that is coupled to a handle. The housing and the blade or blades is referred to as a razor cartridge. Some shaving razors have a disposable razor cartridge that is releasably coupled to a reusable handle while others have a handle and a razor cartridge that are intended to be permanently coupled and disposed of as a single unit.
In recognition of the fact that surfaces to be shaved are not perfectly planar, razor cartridges have been designed to compensate for this during shaving. Commercially successful solutions fall into two broad groups. In a first group, the entire housing and the blades are designed to flex along their length during use. Notable examples of this are disclosed in U.S. Pat. Nos. 5,003,694 (to Chen), 6,182,366 (to Richard) and 6,772,523 (to Richard et al.). In a second group, the blades themselves, mounted to rigid supports, are permitted to move within the rigid cartridge housing away from the surface being shaved. In one sub-class the blades may move independently of each other, notable examples being disclosed in several patents to Jacobson, for example U.S. Pat. No. 4,586,255. An example of a blade attached to a rigid support from the Jacobson art is shown in FIGS. 1 & 2. The blade and the support are labeled as such. These drawings are shown to demonstrate that the support for the razor blade is substantially rigid along its length. In a second subclass the entire set of blades is permitted to move as a group within the rigid cartridge housing away from the surface being shaved by movement of the rigid support in relation to the housing. Notable examples of this second sub-class are the disclosed in U.S. Pat. Nos. 5,253,420 and 5,251,376, both to Althaus et al.
Currently, the state of the art for commercially successful devices is to provide a razor cartridge including three or more blades mounted within the housing. In the first group, noted above, with an increasing number of blades, plus obligatory mounting structure for the blades, the cartridge becomes less able to flex during use. Further, to maintain critical dimensional relationships between the skin contacting parts of the housing and the cutting edges of the blades it is desirable that the razor cartridge flexes only about a single plane. As the number of blades within the housing increases, the front to back dimension of the housing increases, that is, the dimension in the direction of travel of the razor cartridge. Thus, while the flexing of this razor cartridge may help it conform to lengthwise irregularities of the surface being shaved, it cannot conform to front to back irregularities. In the second group, the blade or blades are attached to a rigid support such that the supported blade or blades are substantially inflexible along their length and consequently their edges are maintained substantially straight. This second group's ability for its blade or blades to conform to a non-planar surface is limited to one end (defined lengthwise along the razor cartridge) of the blade or blades moving relatively more than the second end of that blade within the housing. The Jacobson devices disclosed in '255 etc have their blade and support assemblies independently spring mounted relative to each other and are therefore are able to conform to front to back irregularities of the surface being shaved. However, these devices have limited conformance to lengthwise irregularities in the surface being shaved as previously described.
Therefore, there is a need in the art to provide a razor blade and support assembly for use in a razor cartridge that can better conform to lengthwise as well as front to back irregularities in the surface being shaved.